The present invention relates to a device for producing multiple tube or multiple channel structures of thermoplastic material. These structures can be defined, in a general manner, in the following way: they are structures formed by tubes or channels which are parallel, continguous and separated by thin or thick walls. The form of the tubes or channels can be the surface described by a straight line or generatrix displaced parallel to itself while following a closed curve referred to as a directrix. The shape of the directrix can be round, oval, elliptical or polygonal, for example. The directrix form especially preferred is the hexagon, the multi-channel structure thus defined then being of the honeycomb type.